Evaluation of Sensitivity and Specificity of the Method Cefoxitin-disk Diffusion in Detection of Methicillin-resistant Staphylococcus Aureus in Clinical Samples of Two Hospitals, Tehran, Iran

作     者：Saeedreza Jamali Moghadam SIYAHKALI Omid DADRAS Zoha ALI SeyedAhmad SEYEDALINAGHI Nilofar HEJAZI 

作者机构：Ziaeian Hospital Tehran University of Medical Sciences Tehran Iran Department of Global Health and Socioepidemiology Graduate School of Medicine Kyoto University Japan Iranian Research Center for HIV/AIDS Iranian Institute for Reduction of High-Risk Behaviors Tehran University of Medical Sciences Tehran Iran 

出 版 物：《国际转化医学杂志（英文版）》 (Journal of International Translational Medicine)

年 卷 期：2018年第6卷第3期

页      面：141-143页

学科分类：1002[医学-临床医学] 1001[医学-基础医学(可授医学、理学学位)] 100214[医学-肿瘤学] 10[医学] 

主　　题：Staphylococcus aureus Methicillin-resistant Disk diffusion Polymerase chain reaction 

摘      要：Background: The rapid growing rate of Methicillin-resistant Staphylococcus aureus (MRSA) infection is a noticeable phenomenon worldwide and has become a global concern of substantial emphasis. A reliable, accurate and rapid test for the detection of MRSA is important for both therapeutic as well as control measures. This study aimed at comparing the phenotypic (disk diffusion) and genotypic (polymerase chain reaction) methods for the expeditious diagnosis of methicillin-resistant strain samples isolated from patients admitted at Tehran Central Hospitals. Materials and methods: Through a cross-sectional study a total of 150 samples were collected and tested from the patients admitted at Tehran hospitals located in central Tehran between 2014-2015. The isolated samples sensitivity to Cefoxitin disks was confirmed through disk diffusion. Polymerase chain reaction (PCR) method was performed as the Gold Standard test to identify the specimens with mecA gene presence. Results were compared based on sensitivity and specificity by application of chi-square test in SPSS software (version 22). Results: Eighty-three percent of 150 collected samples tested resistance for Cefoxitin applying Cefoxitin disk diffusion *** of the resistant samples to Cefoxitin were negative for the mecA gene; whereas 80％ of the samples were proven positive for mecA gene using PCR. Sensitivity, specificity and positive and negative predictive values of disk diffusion in comparison to PCR were 100％, 85％, 96％ and 100％, respectively. Conclusion: Findings indicated that Cefoxitin disk diffusion method is a simple phenotypic method; however, it has an acceptable sensitivity compared to the PCR method. Therefore, it is recommended for the detection of MRSA. The existence of strains resistant to Cefoxitin without mecA gene suggests the emergence of either a new resistance strain or mutation in MRSA.